AstraZeneca has unveiled full results from two successful late-stage trials of its experimental chronic obstructive pulmonary disease (COPD) therapy, fueling expectations that the drug could generate billions in revenue. The biopharmaceutical candidate, tozorakimab, is currently under priority review by the U.S. Food and Drug Administration, with an anticipated approval in the first quarter of 2027.

Administered once every four weeks, the biologic broadly reduced exacerbations in COPD patients. Ruud Dobber, President of AstraZeneca's BioPharmaceuticals division, said in an interview: "We are confident that a large number of COPD patients can benefit from this new medicine." When added to existing inhaled standard-of-care treatments, the therapy reduced moderate exacerbations by 29% and severe exacerbations by 34% in former smokers, the primary study population. In the broader cohort that included both current and former smokers, the drug cut moderate exacerbations by 30% and severe episodes by 29%, all outperforming placebo.

COPD is a progressive lung disease characterized by obstructed airways and breathing difficulties. The full dataset strengthens expectations that this could become a breakthrough therapy in the respiratory field. According to AstraZeneca, roughly 16 to 26 million people in the U.S. are living with diagnosed or undiagnosed COPD, making it the nation's fifth-leading cause of death.

Where the blockbuster case begins

AstraZeneca recently raised its peak-sales projection for the drug to above $5 billion, supporting its broader goal of reaching $80 billion in total revenue by 2030. Chief Executive Officer Pascal Soriot said the therapy has the potential to reach a vast patient base. "We believe peak sales could exceed $5 billion, driven by a substantial unmet medical need," Soriot stated. "The underdiagnosis of COPD is widespread, and we need to improve diagnostic rates. Adoption of biologics in this space remains severely limited—only about 10% of patients receive biologic therapy, compared with 30% to 40% penetration for asthma biologics in some countries. The growth potential here is enormous."

The optimism stems from the drug's broader applicability. Existing COPD biologics like Dupixent, developed by Regeneron and Sanofi, and GSK's Nucala, are only approved for patients with elevated eosinophil levels. Dr. MeiLan Han, a pulmonologist at the University of Michigan Health System and a study investigator, noted: "A large number of patients do not qualify for the two currently marketed biologics." Dobber added that tozorakimab's wide eligibility profile could truly reshape the COPD treatment landscape.

Both trials enrolled current and former smokers, covering all eosinophil levels and all severities of lung function impairment. Dobber noted that no biologic is currently available for COPD patients with eosinophil counts below 150. Published research suggests that patients with lower eosinophil levels—especially under 100 to 150—tend to have a poorer response to inhaled therapies. Subgroup analyses from the trials showed a 23% reduction in moderate-to-severe exacerbations in patients with eosinophils below 150, a 34% reduction in those with levels of 150 or above, and a 43% reduction in patients with 300 or higher.

Why the target was widely dismissed

Tozorakimab targets the IL-33 protein, which drives inflammation and mucus production—two core mechanisms in COPD. Several companies have pursued IL-33 inhibitors, but most have delivered underwhelming results, leading many investors and researchers to doubt the target's viability. Soriot recounted during a second-quarter earnings call: "No one was bullish on tozorakimab. Our internal probability of success was low, and the market expected the drug to fail. Before the data was released, consensus expectations left almost no room for success. Yet the medicine ultimately succeeded."

AstraZeneca attributes the drug's success where others failed to its differentiated mechanism of action. Earlier candidates largely blocked a single inflammatory pathway. This antibody, by contrast, inhibits two independent IL-33 pathways simultaneously—addressing not only inflammation but also excessive mucus secretion and airway damage, targeting the multiple pathologies of COPD. The company believes this broader mechanism is what allows the drug to reduce exacerbations across a wide variety of patients, reversing years of setbacks for this drug class.

Dr. Han said that from a prescribing perspective, she would now consider using the drug for patients with low eosinophil counts. However, questions remain about how the new medicine will be positioned against existing biologics for patients with elevated eosinophils. There are currently no head-to-head trials, and once the drug hits the market, clinicians will need to determine whether to use it as first-line or later-line therapy. Han expressed a desire for additional subgroup analyses to guide clinical decisions. "I'm very encouraged by this data, but I'm pushing the company for more granular subgroup results to understand how to maximize patient benefit and support optimal decision-making," she said. "There are still major open questions, including how clinicians will choose between treatments and how the GOLD committee will ultimately update its clinical guidelines."

The GOLD committee, or the Global Initiative for Chronic Obstructive Lung Disease scientific committee, is responsible for developing and updating international guidelines for COPD diagnosis, management, and prevention. Dobber revealed that regulatory submissions for the COPD indication are underway in major markets including the European Union and China, while a Phase II trial for severe asthma and a Phase III trial for severe viral lower respiratory tract disease are also progressing. "I firmly believe this could become one of the largest respiratory products in AstraZeneca's history," Dobber said.

He also highlighted the growing threat of air pollution and wildfire smoke, which can damage the lungs and increase both the risk of developing COPD and the frequency of exacerbations. Smoking remains the leading cause of COPD, but environmental exposures are often overlooked. "Not all patients have a smoking history," Dobber noted, pointing to fine particulate matter from sources like wildfire smoke that can irritate vulnerable lungs. He hopes the compelling clinical data will raise public awareness of COPD's severity and drive efforts to reduce modifiable risk factors across society.